1. The Field of the Invention
The present invention relates to an apparatus and method for controlling operating conditions of an on-vehicle generator.
2. Description of the Prior Art
A generator control apparatus has been known which is for use in an automotive vehicle having an engine and which detects operating conditions of an on-vehicle generator (hereinafter simply referred to as a “generator”) and issue an alarm to inform a driver of the automotive vehicle about occurrence of a trouble in the generator. Further, it is known that there are a generator control apparatuses for use in an automotive vehicle having an engine and a battery, which detects operating conditions of not only a generator but also an on-vehicle battery (hereinafter simply referred to as a “battery”), and issue an alarm to inform a driver of the automotive vehicle about occurrence of a trouble in either the generator or the battery, if at least one of an output voltage of the generator and that of the battery does not reach their corresponding predetermined values.
As one of the latter known generator control apparatuses, there is a known generator control apparatus includes an operating condition detecting unit and an alarm issuing unit. The operating condition detecting unit detects an evidence that the generator starts to generate electric power and output voltages of the generator and the battery. The alarm issuing unit that issues an alarm by, for example, winking a charging lamp if at least one of the output voltages of the generator and the battery is lower than a predetermined value.
A key switch of an automotive vehicle outputs an ignition signal to a starter of an engine of the automotive vehicle to energize the starter. A generator and a battery are usually provided in the vehicle in order to supply electric power to electric loads installed in the automotive vehicle. Further, the generator and the battery assist the engine to start to rotate by activating the starter of the engine. In order to start up the automotive vehicle, a driver of the automotive vehicle turns on the key switch to output the ignition signal to the starter. Because the generator is driven by the engine, the generator starts to generate electric power immediately after the activation of engine. When the driver turns off the key switch, the starter of the engine stops its operation. Since the starter consumes a large amount of electric power, if the starter continues to run even after the generator has been activated, it may be occurred that an output voltage of the battery or the generator cannot reach a sufficient level to supply an enough electric power to the electric loads. If the generator control apparatus is configured to issue the alarm to inform the driver of the automotive vehicle about occurrence of a trouble in the generator when the generator does not generate an enough output voltage, the alarm is issued to the driver by, for example, winking of a charging lamp. However, this situation is obtained in some troubles in the generator and the battery.
In the generator control apparatus disclosed in Japanese Patent Laid-Open Publication No. 2006-25558, even if the output voltage of the generator or that of the battery is lower than a predetermined value after a generator becomes to be in a running state, it is prevented from issuing an alarm to inform the driver of the automotive vehicle about occurrence of a trouble in either the generator or the battery until a predetermined time has elapsed from a starting time when the generator of the vehicle becomes to be in the running state. Surely, a voltage drop of the generator is one of the abnormal operating conditions. However, as discussed above, even if the output voltage of the generator is lower than the predetermined value, especially when the engine is activating, the generator may have none of troubles. Therefore, if it is prevented from issuing an alarm to inform the driver of the automotive vehicle about occurrence of a trouble in either the generator or the battery until a predetermined time has elapsed from a starting time when the generator of the vehicle starts to generate electric power, the driver of the vehicle is freed from having to worry about the trouble of the generator or the battery of the vehicle.
In more detail, the generator control apparatus disclosed in Japanese Patent Laid-Open Publication No. 2006-25558 has an operating condition detecting unit, a comparing unit, an alarm issuing unit, and an alarm stopping unit. The operating condition detecting unit detects the output voltage of the generator and that of the battery as an operating condition of the generator. Hence the operating condition detecting unit can determine whether or not the generator becomes to be in a running state. In more detail, the operation detecting unit determines whether or not the generator becomes to be in the running state based on a phase voltage of an armature winding of the generator. If the phase voltage of the armature winding becomes larger than a predetermined value, the operation detecting unit concludes that the generator becomes to be in the running state. The comparing unit compares the output voltages of the generator and the battery to a predetermined value. If the comparing unit concludes that the output voltage of the generator or the battery is small compared with the predetermined value, the alarm issuing unit issues an alarm to inform the driver of the automotive vehicle about occurrence of a generator trouble or battery trouble over a predetermined period after the comparing unit has concluded the generator becomes to be in the running state. The alarm stopping unit stops alarm issuing such as winking of the charging lamp until a predetermined time has elapsed from a start time of generating electric power by the generator. That is, the generator control apparatus described above can prevent from misjudging whether or not the generator or the battery has some trouble in particular after the generator becomes to be in the running state. Therefore, by using the generator control apparatus disclosed in Japanese Patent Laid-Open Publication No. 2006-25558, the driver of the vehicle is surely freed from having to worry about the trouble of the generator or the battery of the automotive vehicle when the output voltages of the generator and the battery greatly fluctuate because the generator and the battery of the automotive vehicle do not reach their steady state.
However, the generator control apparatus issues an alarm if the operating condition detecting unit intermittently detects the output voltage of the generator is low compared to the predetermined value and concludes that the generator intermittently stops to generate electric power just after the engine is activated, that is, the generator starts to generate electric power at which a large fluctuation of a rotation speed of the engine can appear. In a period between a time when the generator starts to generate electric power and a further time when the generator becomes to be in a running state, the rotation speed of the engine can fluctuate greatly. That is, if the phase voltage of the armature winding drops instantaneously due to the large fluctuation of the rotation speed of the engine, the generator control apparatus issues an alarm to inform a driver of the automotive vehicle about generator trouble.